This invention relates generally to automobile body reinforcement arrangements and, more particularly, to a one-piece plastic support bracket supporting a heat expandable closed cell sealer block operative, upon being foamed-in-place, to stiffen a vehicle exterior panel relative to an underlying spaced body substructure.
An example of a known vehicle heat expandable reinforcement bracket assembly is indicated generally at 10 in prior art FIG. 1, wherein the bracket assembly is shown prior to attachment to an inner partition 11 of a vehicle substructure 12 (FIG. 3). With reference to FIG. 2 a vehicle metal fender panel 14 is provided for mounting on portions of the vehicle substructure 12 as shown, for example, in U.S. Pat. No. 4,973,102 issued Nov. 27, 1990 to Bien an inventor of the present invention. The fender panel 14 has an upper aft corner portion supported in a spaced manner from the metal substructure inner partition 11. To prevent the upper corner portion from being easily deflected into an underlying space 16, with the possibility of paint chipping and rattles, the bracket assembly 10 was designed to be installed on a vehicle assembly line.
The prior art bracket assembly 10 comprises a sheet metal bracket 20 formed into a double-L cross-section defining an upright plate 22, having an outboard extending lower flange 24 an inboard extending upper flange 26. FIG. 1 shows the upper flange 26 formed with a central inboard projecting tab 28 operative to sit on an upper horizontal flanged surface 30 of the partition 11 (FIG. 2) upon the bracket plate 22 being positioned in flush contact with partition opposed surface 31. A push-in "Christmas tree" type plastic fastener 32 is provided for insertion in plate hole 34 and aligned partition hole 36 to retain the bracket 20 on the vehicle substructure. It will be noted that the bracket plate 22 has an elongated slot 38 lanced therein for a purpose to be explained.
With reference to FIG. 1 an elongated rectangular sectioned sealer block 40, formed of heat expandable die-cut rubber-based sealer material, has its one side face bonded by heat-staking to the bracket plate opposed outer surface while the block bottom face is heat-staked to the upper surface of the lower flange 24. It will be noted in FIG. 1 that the heat expandable sealer block 40 has its outboard lower edge formed with a co-extensive integral foam directing flap 42 extending upwardly and outwardly at about a 45 degree angle therefrom. Further, FIG. 1 shows the assembly 10 being loosely enclosed by a flexible plastic mesh netting 44. The netting 44 is retained upon being draped over the bracket with its overlapped ends pierced and by the fastener 32 prior to the fastener being inserted in the aligned holes 34 and 36. The fastener 32 has a separate washer 48 for sealing the holes 34 and 36.
In operation, as each vehicle body is advanced on an assembly line, a pair of bracket assemblies 10 are mechanically attached on their associated right and left substructure partitions 11 prior to the vehicle body being spray painted. Upon each vehicle body being subsequently primed and heat cured to a predetermined temperature in a drying oven the heat expandable sealer block 40 undergoes thermal expansion into a closed-cell flexible rubber-based thermofoamed stiffener 46 bridging the space 16 between the vehicle panel 14 and the metal bracket 20. The foamed stiffener 48 provides high compressive resistance together with adhesive characteristics such that upon its thermal expansion it achieves a permanent adhesive bond to the inner surface of the panel 14 and the opposed substructure. An example of one type of heat expandable material suitable for the present invention may be purchased from RuVan Inc., 1175 Diamond Avenue, Evansville, Ind. 47711 under their vendor code: Type A - B-237E.
In a similar manner the thermofoamed closed cell stiffener 48 expands through the plate slot 38 adhesively bonding to the outer surface of the metal substructure partition 11. As a result the foamed-in-place stiffener 48 provides high compression resistance preventing the fender panel 14 from being easily deflected into the space 16. It will be noted that the mesh netting is required to prevent any of the heat activated sealer material 46 from flowing downwardly past the guide flap 42 during the time the sealer material is undergoing thermal expansion and curing.